Bonding Under Pavers

[Dougwill]

I am in the process of renovating our 40+ year old steel wall vinyl liner pool. The concrete deck has been demoed out and they just finished the trenching around the pool for the new plumbing and low voltage lighting (hayward colorlogic 320).

This is our family pool so I want to make sure that everything is safe, not just meeting code. The pool originally had a raised coping/liner track and we are updating it to have paver bullnose coping. My mason is pouring a 12" deep concrete footer around the outside of the pool to support the new paver coping which will be set in mortar ontop of the footer. The pool deck will be pavers set in sand over QP base.

My plan is to bond the pool on all 4 sides, jump to a lay-in rebar grounding clamp in 4 spots and then either a single copper loop, multiple copper loops, or copper grid. My pool guy and an electrician I know are both saying that a single copper loop is fine and meets code, but I am thinking about going with the copper grid or multiple loops for extra safety, especially knowing there will be young kids in the pool.

If I do go with the copper grid, does the 1' of paver coping set on concrete with bonded rebar count as the first foot, meaning I would only need 2' of copper grid outside this to get the 3' total?

Does the copper grid provide significantly better protection than say, 3 loops of copper spaced out between the back of the coping and 3' from pool edge? The pool is 20x40, and I can get 500' of copper for about $275 to complete three loops and have plenty left over for bonding to other equipment, vs 150' of 2' wide grid for about $800.

 

[woodyp]

Are you sure it's a steel wall and not maybe an aluminum wall? Welcome to the forum.

 

[Bill1974]

More copper is not a problem. As long all all the rebar, metal items and equipment are bonded with a solid 8 awg or larger copper wire you are to code I believe. I am not famlilar with the requirement to have bonding out to 3 ft from the pool (i'm not saying it's not required or arguing against it, i don't recall reading it in the NEC, I redid my pool just like you a couple of years ago, but I went slab under all the pavers and bonded all the wire mesh in the slab). Making sure all the equipement is bonded and GFCI protected is important. Do you have issues with stray/fantom voltage in or around you pool?

It started out as a liner replacement and replacing the coping!

 

[Dougwill]

More copper is not a problem. As long all all the rebar, metal items and equipment are bonded with a solid 8 awg or larger copper wire you are to code I believe. I am not famlilar with the requirement to have bonding out to 3 ft from the pool (i'm not saying it's not required or arguing against it, i don't recall reading it in the NEC, I redid my pool just like you a couple of years ago, but I went slab under all the pavers and bonded all the wire mesh in the slab). Making sure all the equipement is bonded and GFCI protected is important. Do you have issues with stray/fantom voltage in or around you pool?

It started out as a liner replacement and replacing the coping!

I did have a stray voltage issue at one point, and I got a slight shock in the pool. The pool was put in in the 70's and they had three circuits in a single conduit including the 220 for the pool, with no GFCI. I tracked it down to a hot that was putting voltage onto the ground wire. I removed that circuit and have the pool running off a 120V pump on a GFCI. No issues since then.

The 3' from the pool comes from the new option for perimeter surface bonding in NEC 2020 as well as some jurisdictions requiring it under pavers.

I know the single solid 8 AWG meets code, just trying to play it safe with 2 young kids and families with young kids that will be using the pool.

 

[Dougwill]

Are you sure it's a steel wall and not maybe an aluminum wall? Welcome to the forum.

Looks like steel, need to check with a magnet. It was built in the 70's

 

[Bill1974]

The bonding intended to make all the areas aroudn the pool equal in potential. Risk of shocks occurs when they they is a difference in potential between two touch points. The GFCI is checking to make sure the current coming from the supply matches the current returning to it, If it doesn't match it's going somewhere it's not supposed to and that is what causes the tripping. At one point in time I don't think GFCI was reqired on 240V circuits or it was misunderstood and a GFCI was not installed. I am not sure what older versions of the code stated but, recent ones state that is there is a 150v difference between line and ground a GFCI is required. A typical 240V supply is two legs of 120V that are 180° out of phase and that is where the 240V nominclature comes from, but the line to ground is still less than 150V and needs to be GFCI protected. There are some services that supply 240V with a line at 240V and a neutral, but this is not a typical residential service.